A passenger conveyor typically includes a series of passenger platforms or steps which are driven in an endless path between horizontally spaced landings. The passenger conveyor includes a main body frame supported by the floors or other support structures of a building, for instance, and conventionally has track means for the passenger platforms to guide the platforms along a path between the landings Typically, the track means include a support track for support rollers mounted to the respective passenger platforms, and, in some instances, guide rollers movable along a guide track. Usually, the overall passenger conveyor construction includes a balustrade about which handrails are circulated in an endless path generally in synchronism with the movable platforms. Kick skirts conventionally run along opposite sides of the conveyor, with the passenger platforms being disposed between the skirts. Guide mechanisms in various forms normally are provided to maintain the moving passenger platforms spaced from the side skirts in order to avoid any dragging engagement between the platforms and the skirts.
One of the continuing and major problems with passenger platforms of the character described above, is the inability to maintain a consistently small clearance between the moving passenger platforms and the side skirts to prevent foreign objects from lodging therebetween and still prevent dragging engagement between the platforms and the skirts. Most uniform building codes require a 3/16 inch maximum clearance between the platforms and the skirts. This maximum limit is required to prevent most foreign objects from lodging in the side gaps between the platforms and the skirts However, that maximum limit still is insufficient to prevent many smaller objects from wedging into the gaps. It is known that the maximum clearance allowable under such uniform codes would be made smaller, but industry has not found any effective guide mechanism to reduce the clearance without creating dragging engagement between the platforms and the skirts. The tolerances during manufacture and/or assembly simply are too great for such massive components.
Heretofore, guide mechanisms for passenger conveyors predominantly have incorporated guide tracks and guide rollers mounted at opposite sides of the passenger platforms. Consequently, there must be a separate track setting at each side of each platform or a setting based on the distance between the horizontally spaced guide tracks and/or guide rollers In other words, these types of guide mechanisms could be called "bumper rail" systems in that there must be some allowance between the two opposite settings of each platform or else there would be a constant binding between the horizontally spaced, opposing guide mechanisms.
This invention is directed to solving the above problems by providing a monotrack guide rail system which has been found capable of reducing the gap clearance between the passenger platforms and the conveyor side skirts to on the order of 1/16 inch.